A new bioprinting method developed at the Wyss Institute for Biologically Inspired Engineering at Harvard University and the Harvard School of Engineering and Applied Sciences (SEAS) creates intricately patterned ...

Tibetans were able to adapt to high altitudes thanks to a gene picked up when their ancestors mated with a species of human they helped push to extinction, according to a new report by University of California, ...

(Phys.org) —A team of Stanford scientists has developed an entirely non-invasive technique that provides a view of blood flow in the brain. The tool could provide powerful insights into strokes and possibly ...

In spite of its dangerous reputation, cholesterol is in fact an essential component of human cells. Manufactured by the cells themselves, it serves to stiffen the cell's membrane, helping to shape the cell ...

(Phys.org) —For the first time, scientists have turned human skin cells into transplantable white blood cells, soldiers of the immune system that fight infections and invaders. The work, done at the Salk Institute, could ...

If you believe this article from Collective Evolution, a site that claims to be "one of the worlds most popular alternative media company", there is currently DNA from genetically modified plants floating ...

What doesn't kill cells may make them stronger—or considerably more flexible, at least. New findings from Haruko Obokata of the RIKEN Center for Developmental Biology in Kobe and Charles Vacanti at Brigham ...

Components of human endothelial cells stained for identification. In red is the 'actin' protein that allows the cells to move, adhere, divide and react to stimuli. In blue are the cell nuclei containing DNA.

In a paper published today by the prestigious journal, Nature Methods, biologists at the University of Luxembourg, Tampere University of Technology and the Institute for Systems Biology in Seattle, USA, have created the bi ...

A genome-wide analysis searching for evidence of long-lived balancing selection—where the evolutionary process acts not to select the single best adaptation but to maintain genetic variation in a population—has uncovered ...

Researchers at the University of Maryland School of Medicine have identified a peptide, or protein, derived from Pacific cod that may inhibit prostate cancer and possibly other cancers from spreading, according to preclinical ...

(Phys.org) —Botryllus schlosseri, a small sea creature, can regenerate its entire body from its blood vessels alone. Stanford researchers hope that sequencing its genome will lead to advances in regenerative ...

Blood

Blood is a specialized bodily fluid that delivers necessary substances to the body's cells — such as nutrients and oxygen — and transports waste products away from those same cells.

In vertebrates, it is composed of blood cells suspended in a liquid called blood plasma. Plasma, which comprises 55% of blood fluid, is mostly water (90% by volume), and contains dissolved proteins, glucose, mineral ions, hormones, carbon dioxide (plasma being the main medium for excretory product transportation), platelets and blood cells themselves. The blood cells present in blood are mainly red blood cells (also called RBCs or erythrocytes) and white blood cells, including leukocytes and platelets. The most abundant cells in vertebrate blood are red blood cells. These contain hemoglobin, an iron-containing protein, which facilitates transportation of oxygen by reversibly binding to this respiratory gas and greatly increasing its solubility in blood. In contrast, carbon dioxide is almost entirely transported extracellularly dissolved in plasma as bicarbonate ion.

Vertebrate blood is bright-red when its hemoglobin is oxygenated. Some animals, such as crustaceans and mollusks, use hemocyanin to carry oxygen, instead of hemoglobin. Insects and some molluscs use a fluid called hemolymph instead of blood, the difference being that hemolymph is not contained in a closed circulatory system. In most insects, this "blood" does not contain oxygen-carrying molecules such as hemoglobin because their bodies are small enough for their tracheal system to suffice for supplying oxygen.

Jawed vertebrates have an adaptive immune system, based largely on white blood cells. White blood cells help to resist infections and parasites. Platelets are important in the clotting of blood. Arthropods, using hemolymph, have hemocytes as part of their immune system.

Blood is circulated around the body through blood vessels by the pumping action of the heart. In animals having lungs, arterial blood carries oxygen from inhaled air to the tissues of the body, and venous blood carries carbon dioxide, a waste product of metabolism produced by cells, from the tissues to the lungs to be exhaled.

Medical terms related to blood often begin with hemo- or hemato- (also spelled haemo- and haemato-) from the Ancient Greek word αἶμα (haima) for "blood". In terms of anatomy and histology, blood is considered a specialized form of connective tissue, given its origin in the bones and the presence of potential molecular fibers in the form of fibrinogen.